Captive tube closure



June 4, 1957 F. BR'AUN CAPTIVE TUBE CLOSURE?- Filed March 7, 1955 F250 H BRAl/N.

ATTORNEY United States Pate fh CL SU Fred H. Braun, Los Angeles, Calif. Application March 55 Stfi lN e-Lfll 'Thisinvention relates to acaptivetube closure and deals more particularly'with aclosure for collapsible-tubes that dispense paste.

-An=-object of the present inventionis to-provide a tube structure in which the cap thereof is non-removable although assembly of the cap onto the dispensing end of the tube is easily effected.

Another object of the invention is to provide a tube structure in which the cap is provided with an inwardly constricting annulus that seals between the cap and the tube neck and which is adapted to expand over the neck to facilitate easy assembly of the cap onto the dispensing end of the tube.

The invention also has for its objects to provide such means that are positive in operation, convenient in use, easily installed in a working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description. However, the drawing merely shows and the following description merely describes preferred embodiments of the present invention, which are given by way of illustration or example only.

In the drawing, like reference characters designate similar parts in the several views.

Fig. l is a plan view, partly in plan section of a captive tube closure according to the present invention.

Fig. 2 is an elevational view thereof in quarter section and shown in paste sealing position.

Fig. 3 is a fragmentary side sectional view showing the tube closure in open or dispensing position.

Fig. 4 is an enlarged fragmentary detail sectional view of a portion of the cap of said tube closure.

Fig. 5 is a similar view of a modified form of construction.

The drawing shows a generally conventional tube having a shoulder 11 from which extends a tubular neck 12, the latter being conventionally circular in cross-section. Said tube, as is usual, is made of a soft metal, of which lead, zinc, and aluminum and alloys thereof are examples.

According to the present invention, said tube is pro vided with external threads 13 outward of the neck 12, a paste-dispensing nozzle or end 14 outward of said threads, and a cap 15 to serve as a closure for the end 14 and provided with a leakage-sealing annulus 16 cooperating with the neck to seal against leakage of paste between said neck and cap.

The threads 13 may be provided on an annular enlargement 17 of said neck, the same defining a downwardly facing annular shoulder 18.

The paste-dispensing end 14 is shown as a conical portion 19 extending from the upper end of enlargement 17 and terminating in a closed and preferably rounded end wall 20. As shown, said conical portion is provided with a set of ports or openings 21. The structure shown is 2,794,581 7 Patented. June. .4, .1957

The. number and size of said openings .,may vary-,- ;as zdq re I ,As. shown inFigs. 1 to. 4, rtheecap 15,,is preferably formed of aplastic material, of .which polyethylene and styreneareex ples, so as to have a degree of elasticity that enables circumferentialstretchoflimited degree. and effective SeaIiHg:;Of ports or openings .21. The desired consistency of the material maybe likened. to a semihard rubberso aseto, beform-retaining and yet afford .yield and-stretch of thin. sections, thereof. The same may be opaqueor not, as-.desir.ed.

-:T e s p nrovide w than ounward yknurled a nu a bo,dy;22.,that.has; intcrnaL-threads 23..engaged with the th sa s f e;- aAn upp .co icalz-ext s onfl ofi he body 22 isdesigned toconforrn to audit overthe .QQIli 1L'rPQI' U Q; of .said tube. Saidexte ion. 4- orme rwi h. dispsnsingnn nin 5' nug w i hs Wa l 2% lit eube is: a apt d 0 ex e d- It will be clear that threading said cap over the tube end until extension 24 is seated against portion 19, causes said extension to close openings 21. Because of the conical engagement extension 24 is adapted to stretch over the conical portion 19 and thus effectively seal said openings against leakage (see Fig. 2). By backing OK on the cap and separating conical extension 24 from portion 19, the openings 21 are opened and the paste in tube 10 may be forced outwardly through dispensing opening 25 (see Fig. 3).

It is not practicable to make the fit between threads 13 and 23 too tight. Thus, ordinarily, paste may leak between the threads and around tube neck 12. The annulus 16 is provided for obviating such leakage, the same comprising a thin inreaching flange 26 that normally defines a central opening 27 that is smaller than the diametral size of the tube neck. However, said flange has considerable flexibility and suflicient stretch so as to assume the stretched and flexed position of Figs. 2 and 3 from the relaxed position of Fig. 4. Thus, said flange efiectively seals around the tube neck and said seal is rendered still more effective by pressure of paste that leaks past the threads and fills the annular groove 28 defined between the cap body and the flange 26.

As seen from the dot-dash lines of Fig. 4, the flange 28 may be expanded by the threads 13 so as to allow bringing of said flange to the neck side of said thread. Once past the threads, said flange contracts into leakage sealing engagement with the tube neck 12.

As shown in Fig. 5, the cap may be made of metal, as an alternative. Although port sealing between the metal tube end and the metal cap may be somewhat less elficient than before, an acceptable construction may be provided. In this instance, the leakage-sealing annulus 16 may comprise a rubber or similar O-ring 29 that resides in a groove 30 formed in the cap. It will be evident that said ring can expand to pass over threads 13, during assembly of the cap onto the tube nozzle and then contract to seal against the tube neck 12 where the same will be in such sealing contact in all positions of the cap relative to the nozzle. The cap movement is limited by the engagement of extension 24 with conical portion 19, at one end of its movement, and by engagement of annulus 16 with shoulder 18, at the other end of its movement.

While the foregoing has illustrated and described what are now contemplated to be the best modes of carrying out the invention, the constructions are, of course, subject to modification without departing from the spirit and scope of the invention. It is, therefore, not desired to restrict the invention to the particular forms of construction illustrated and described, but to cover all modifications that may fall within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is: 7 V

g '1. A closure for a paste tube having a neck provided withan externally threaded nozzle and said nozzle having at least two paste-passing openings, said closure adapted to 'be engaged over the threads of'the nozzle a' resilient portion on one side of the closure for sealing said nozzle openings, and an elastic and stretchable annulus on the otherside of said closure in resilient paste-sealing contact with the' nozzle neck, said annulus constituting a flange.

2. A closure according to claim 1: said annulus comprising an inreaching flange integrally formed on the closure and defining an opening substantially smaller than the diametral size of both the threads and the neck.

3.. A cap for the nozzle of a dispensing tube having external threads and a circular neck adjacent the threads,

said cap having engagement with the'threads of the nozzle, and an elastic and stretchable annulus carried by the cap, said annulus being a flange and adapted, when stretched, to pass over the threads of the nozzle, and to 7 seal said neck after assembly of cap and nozzle by pressure exerted on said flange by the paste passing from said nozzle.-- a

4. A cap for the nozzle of a dispensing tube having external threads and a circular neck adjacent the threads, said cap having engagement with the threads of the nozzle, and an elastic and stretchable annulus carried bytthe cap, said annulus being adapted, when stretched, to pass over the threads of the nozzle, and to seal said neck after assembly of cap and nozzle, said cap and annulus being integrally formed from a non-metallic elastic material, and the latter comprising an inwardly directed flange responsive to pressure from within the tube to press and seal against the nozzle neck.

References Cited in the file of this patent UNITED STATES PATENTS 1,890,441 Hickman et a1. Dec. 6, 1932 1,977,623 Corbin Oct. 23, 1934 2,061,124 Walther Nov. 17, 1936 2,348,014 Mallard May 2, 1944 2,667,992 Hammond et al Feb. 2, 1954 

